Plate-printing press



( 1 v 2 Sheets-Sheet 1.

J. TREGURTHA. PLATE PRINTING Puss. 9 l

W Patented Apr. 11,1882. 1:111 11.11:

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by M

Witmsses: Mm $9? 2 Sheets-Sheet 2'.

J.TREGURTHA.

PLATE PRINTING PRESS.

(No Model.)

No. 256,413. Patentefi A 1211,1882;

In W 1 11 U ITE STATES JAMES TREGURTHA,

PATE T OFrIc-a' 1 PLATE-PRINTING PRESS.

SPECIFICATION forming partof Letters Patent N0. 256,413, dated April 11, 1882.

' Application filed November 14, 1 881. (N0 model.)

To all whom it may concern: 1

Be it'known that I, JAMES TREGURTHA, of

- Boston, in the county of Suffolk and State of Massachusetts, have invented a new and useful Improvementin Plate-Printing Presses,,of which the following, taken in connection with the accompanying drawings, is a specification.

' which will be best understood by reference to I tudinal section on line yy on Fig. 1.

the description of the drawings, in which- Figure l is a vertical transverse section on line m x on Fig. 2. Fig. 2 is a vertical longi- Fig. Sis a plan of a portion of the plate-carrying bed and blank and the pivoted spring-supported hook by which said plate-ca rryin g bed is moved to the rear to give the impression.

A A are the side frames of the machine, connected together by the tie-rods or girts a a, and carrying in suitable bearings therein the bed-supporting cylinder B and rolls 0 O and the impression-cylinder D.

The bed-supporting plank E is mounted upon the cylinder B and rolls 0 C, and is guided in its forward and backward movements by the ribs b b in a well-known manner. This plank v carries near its front end the bed F, to the frontend of which is secured the gage 0, against which the front edge of the plate d is placed, as shown.

Beneath the plank E, and attached thereto at their front ends, are two rods, 6 e, the rear ends of which have hearings in and move endwise through stands ff, secured to the rear ends of the frames AA, spiral springs gg, surrounding said rods between the stands ff, and adjustable collars h h on said rods, all constructed and arranged in a well-known manner. The springs g g serve to move the plank toward the front of the machine after each impression, so that the printed sheet may be ,removed and afresh one placed in position on ,the plate.

The cylinder or roll D has turned in its periphery a circumferential groove, 1', the outer wall of which is formed by the radial flange i, which is made somewhat smaller in diameter than the main body of the roll D, the purpose of which will presently appear. A radius-arm, G, is mounted loosely upon the shaft of the roll D contiguous to the flange l, and is secured firmly to the roll D in any desired position by means. of the hook-headed bolt j and the nut j, the head of the bolt engaging with the inner side of the flange i, as shown in 2. .The arm G is-provided with 2. lug, 7c, just above the boltj, the end of which bears against the inner wall of the groove i when the inner side of said arm is pressed hard against the end of the roll -D, and thus 'prevents the strain of the bolt from springing the arm G out ofline. The arm Gr projects beyond the periphery of the roll D, and has set in or formed upon its outer end thestud Z, whichat the proper time in the rotation of the roll .D' engages with the notched forward end of the arm H, which is pivoted atits rear end to the bar I and supported in a horizontal, or nearly horizontal, position by the spring J, as shown in Fig. l. The bar I has formed upon its ander side a rib or lip, which extends longitudinally thereof, and is fitted into the groove m formed in the upper side of the plank E, and said bar is also provided near its front end with a slot, 1;, by means of which and the bolt a said bar maybe firmly secured to and adjusted upon said bed.

As the plates to be printed from on plateprinting presses are widely difi'erentin size, it becomes desirable to adapt the movements of the bed to the length of the plate being printed, and at the same time move said bedin exact unison with the periphery of the impressionroll D, during the time that the plate is moving to the rear after the pressure is applied.

This is done by adjusting the arm G around the axis of the roll D to the desired angle to the flat side of the D roll and adjusting the hook-arm H and the bar I toward or from the front end of the bed E. A graduated and numbered scale is out upon or affixed to the side of the plank E, near the bar I, and simior BOSTON, ASS'IGNOR TO WILLIAM o. DEMAIN, JR., or MEDFORD, MASSACHUSETTS. I v

lar scales are placed upon the corner of the bed F and on outer portion of the end of the D roll, near the groove i, as shown, so that if the plate is six inches long the front end of the bar I is adjusted to the division 6 of its scale, and the arm G is adjusted around the roll D till the front corner of the lug k coincides with division 6 of the scale on the roll D. The ordinary blanket is used on this machine, though not shown, its rear end being secured to the clamps L, and after passing beneath and partially around the roll D has its other end portion heldin an upright, or nearly upright, position by cords passing over pulleys, with weights attached to their other ends, in a well-known manner.

The operation of my improved machine is as follows: The plate to be printed from being secured in position upon the bed F, if its rear edge extends six inches from the gage c, or to division 6 of the scale, the bar I is adjusted so that its front end coincides with division 6 of the scale on the plank E, and the arm Gr is adjusted around the axis of the roll D till the front corner of the lug 7c coincides with division 6 of the scale 011 the cylinder D, when the machine is ready for operation. The plate being properly inked, wiped, and polished, the

paper is placed thereon, and the operator revolves the roll D by means of a hand-wheel, which in practice is secured upon the left-hand end of the shaft of said roll, but not shown in the drawings, till the stud set in the outer end of the arm G engages with the hooked end of the arm H, when the plank E, carrying the bed F and the plate secured thereon, will be moved toward the rear of the machine by the engagement of said arms till the rear edge of the plate passes into the bite between the impression-roll and the bed-roll, which should be at a point on the roll D just six inches from the corner 0, formed by the junction of the flat side of said roll with its circular or cylindrical periphery. A continuation of the rotation of the roll D will cause the plate to be moved toward the rear in exact unison with the movement of the periphery of said roll till the coruer 0 of said roll and the ed go of the plate that rests against the gage 0 have passed beyond the line of pressure between the roll D and bed-supportin g cylinder B, when, the pressure being removed, the springs gg, which have been compressed by the rearward movement of the plank E, react and return the bed and the plate carried thereby to their former positions at the front of the machine, where the printed sheet is removed, when the plate may be again inked, wiped, and polished preparatory to taking another impression.

What I claim as new, and desire to secure by Letters Patent of the United States, is-

1. The roll D, provided with the circumt'en ential groove i and flange or lip i, in combination with the arm G, provided with the high and stud l and looselymounted upon the shaft of the roll D, and the boltj and nutj,all constructed, arranged, and adapted to operate substantially as and for the purposes described.

2. The combination of the roll D, provided with the groove 5, the arm G, provided with the lug L and stud Z, the boltj and nutj, the plank E, the bar I, adjustably secured to said bed, the hook-arm H, and the spring J, all constructed, arranged, and adapted to operate substantially as and for the purposes described.

Executed at Boston, Massachusetts, this 11th day of November, A. D. 1881.

JAMES TREGURTHA. Witnesses:

E. A. HEMMENWAY, WALTER E. LOMBARD. 

